The invention relates to a method and apparatus for forming and bonding decorative skins such as wood veneers and metal foils, as well as synthetic and natural laminates, over shaped articles. According to the prior art, this is achieved by one of three methods. The first method, "profile wrapping", uses a number of rollers which roll the skins onto the shaped article. However, this method is undesirable since the physical details of the shaped article over which the skin is formed are limited depending upon the diameter of the rollers. In addition, this type of equipment is extremely expensive and service intensive.
The second type of prior art method involves the use of a membrane press. In this method, a rubber sheet is stretched over the mouth of a high pressure press. After the press is closed, a gas chamber behind the rubber sheet is pressurized with air, water, or oil, thus forcing the membrane to form to the shape of the shaped article. Although this method allows the laminate to conform to smaller details of the shaped article than possible with profile wrapping, this method is limited to a maximum pressure of around 10 bars. In addition, the membrane press is a very dangerous piece of equipment since the rubber sheet can potentially rupture if the pressure in the gas chamber exceeds the closing power of the press, or if the shaped article has sharp corners. When hot oil is used in the device, the prospect of rupture of the rubber membrane is especially dangerous.
The third type of prior art method involves the use of a piston type pressure chamber. In this method, a piston pushes the article and decorative skin laminate into a forming-medium. The forming-medium then forces the laminate onto the article. Although this method is successful, the charging of the chamber and the pressurizing of the piston are complicated and slow. Further, the steps of heating and cooling the decorative laminate in the chamber are time consuming and energy intensive.